Answer:
555
Step-by-step explanation:
Answer:
4 + x = 12
x = 8
Step-by-step explanation:
4 more than a number is 12
I will represent the mystery number as "x"4 + x = 12
x = 8
A survey of 1100 adults from a certain region asked, "If purchasing a used car made certain upgrades or features more affordable, what would be your preferred luxury upgrade?" The results indicated that 49% of the females and 41% of the males answered window tinting. The sample sizes of males and females were not provided. Suppose that of 600 females, 294 reported window tinting as their preferred luxury upgrade ofchoice, while of 500 males, 205 reported window tinting as their preferred luxury upgrade of choice. Complete parts (a) through (d) below.
a. Is there evidence of a difference between males and females in the proportion who said they prefer window tinting as a luxury upgrade at the 0.05
level of significance?
b. State the null and alternativehypotheses, where π1 is the population proportion of females who said they prefer window tinting as a luxury upgrade and π2 is the population proportion of males who said they prefer window tinting as a luxury upgrade.
Answer:
a) The p-value of the test is 0.0076 < 0.05, which means that there is evidence of a difference between males and females in the proportion who said they prefer window tinting as a luxury upgrade at the 0.05.
b) The null hypothesis is [tex]H_0: \pi_1 - \pi_2 = 0[/tex] and the alternate hypothesis is [tex]H_1: \pi_1 - \pi_2 \neq 0[/tex].
Step-by-step explanation:
Before testing the hypothesis, we need to understand the central limit theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Females:
49% from a sample of 600. So
[tex]\pi_1 = 0.49, s_{\pi_1} = \sqrt{\frac{0.49*0.51}{600}} = 0.0204[/tex]
Males:
41% from a sample of 500. So
[tex]\pi_2 = 0.41, s_{\pi_2} = \sqrt{\frac{0.41*0.59}{500}} = 0.022[/tex]
Test if there is a difference between males and females in the proportion who said they prefer window tinting as a luxury upgrade.
From here, question b can already be answered.
At the null hypothesis we test if there is no difference, that is, the subtraction of the proportions is 0. So
[tex]H_0: \pi_1 - \pi_2 = 0[/tex]
At the alternate hypothesis, we test if there is a difference, that is, the subtraction of the proportions is different of 0. So
[tex]H_1: \pi_1 - \pi_2 \neq 0[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{s}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, and s is the standard error.
0 is tested at the null hypothesis:
This means that [tex]\mu = 0[/tex]
From the two samples:
[tex]X = \pi_1 - \pi_2 = 0.49 - 0.41 = 0.08[/tex]
[tex]s = \sqrt{s_{\pi_1}^2 + s_{\pi_2}^2} = \sqrt{0.0204^2 + 0.022^2} = 0.03[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{s}[/tex]
[tex]z = \frac{0.08 - 0}{0.03}[/tex]
[tex]z = 2.67[/tex]
Question a:
P-value of the test and decision:
The p-value of the test is the probability that the sample proportion differs from 0 by at least 0.08, which is P(|Z| > 2.670, which is 2 multiplied by the p-value of Z = -2.67.
Looking at the z-table, Z = -2.67 has a p-value of 0.0038.
2*0.0038 = 0.0076
The p-value of the test is 0.0076 < 0.05, which means that there is evidence of a difference between males and females in the proportion who said they prefer window tinting as a luxury upgrade at the 0.05.
can I get some help with these please...
Answer: b d a
Step-by-step explanation:
B
D
A
(Click the picture to see math question) please help I’ll mark brainliest
Answer:
g(x) = f(x + 2)
Step-by-step explanation:
The x value has been translated by 2
Feel free to mark it as brainliest :D
what is the vertex of y=ax^2+c
9514 1404 393
Answer:
(0, c)
Step-by-step explanation:
Compare the given equation to the vertex form equation ...
y = a(x -h)^2 +k . . . . quadratic with vertex (h, k)
You have ...
y = ax^2 +c
Matching these forms, we see that h=0, and k=c. Then the vertex is ...
(h, k) = (0, c)
find the radius of a circle
if the circumference is 66cm
Answer:
10.5
Step-by-step explanation:
Find the sum of the first five terms of the geometric series 50 + 25 + 12.5 +
The answer for this question is 6.25
please help will give brainliest
Answer:
B
Step-by-step explanation:
FIND THE MISSING SIDE LENGTHS!!!!!
Step-by-step explanation:
tan 30°= root 3/ 3
r²=x² + y²
r²= 4root3 ² + 12²
r²= 48 +144
r²= 192
ŕ= 8root3
so the bottom is 12...
the other side is 4root3
[tex]4 \sqrt{3} [/tex]
and hypotenuse is 8root3
[tex]8 \sqrt{3} [/tex]
What is the surface area of the cylinder with height 4 in and radius 5 in? Round your answer to the nearest thousandth .
Answer: 282.743 in2
Step-by-step explanation:
solve the equation s - 12 equals 20
ASAP pls
Answer:
s = 32
Step-by-step explanation:
s - 12 = 20
s (- 12 + 12) = 20 + 12
s = 32
Step-by-step explanation:
s-12=20
s=20+12
s=32
Hope it helps.
HELP PLS +10 BRAINLY POINTS (SHOW WORK PLS)
Hi there!
[tex]\large\boxed{\text{System G.}}[/tex]
For a system to have an infinite number of solutions, both expressions must be equal. We can go through each system and determine this:
F:
x + 2 = y
4 = 2y - x
If we rearrange so that both are in the same format, we get:
x + 2 = y
x + 4 = 2y
These cannot be equal, so they do not have infinite solutions.
G:
2y + 6 = 4x
-3 = y - 2x
Rearrange:
2y + 6 = 4x
-y - 3 = -2x
We can try to make the bottom equation look like the top equation by multiplying all terms by -2. We get:
2y + 6 = 4x. This is the same as the top, so G has infinite solutions.
Just to be sure, we can go through the others:
H:
y + 3 = 2x
4x = 2y - 3
Rearrange:
y + 3 = 2x
2y - 3 = 4x. Cannot be equal to the other equation.
J:
y = 2x - 5
y = 2x - 2. Not equal.
The correct answer is G.
please help me asap!!
Answer:
x = 14
Step-by-step explanation:
The polygon given has 6 sides
Sum of interior angles of a 6-sided polygon = 180(n - 2)
substitute n = 6 into 180(n - 2)
Sum of the polygon = 180(6 - 2) = 720°
Thus:
10x + 8x - 16 + 12x - 8 + 7x + 2 + 9x + 4 + 6x + 10 = 720
Add like terms
52x - 8 = 720
52x = 720 + 8
52x = 728
x = 728/52
x = 14
Which Triangles are Congruent and Explain Why.
Answer:
D
Step-by-step explanation:
because I remember doing this before
In a viral pool test it is known that in a group of five (5) people, exactly one (1) will test positive. If they are tested one by one in random order for confirmation, what is the probability that only two (2) tests are needed?
Answer:
[tex]\frac{4}{20}[/tex] or 0.2 or 20%
Step-by-step explanation:
For only two tests to be needed this means that the first test would need to come back as negative and the second test would be to come back as positive. Therefore, to find the probability of this happening we first need to find the probability of each individual test and multiply them together.
The first test needs to come back negative, there are four negative individuals out of the total 5 that are in the group. Therefore, the probability of the first test is 4/5.
Now we remove the individual that has just been tested and we are left with 4 total subjects in the group, of which only 1 is positive. Therefore, the probability of the second test is 1/4. Now we need to multiply these two probabilities together to get the probability of only needing two tests.
[tex]\frac{4 * 1}{5 * 4} = \frac{4}{20}[/tex] or 0.2 or 20%
The probability that the number on the card is a perfect square is
From 2 to 101 , the perfect square numbers are ,
4 , 9 , 16 , 25 , 36 , 49 , 64 , 81 , 100 .Total number of possible outcomes = 100.
Total number of favourable outcomes = 9 .
Hence ,
→ P ( of getting perfect square ) = 9/100
Soren solves the quadratic equation x^2 + 8x – 9 = 0 using the quadratic formula. In which step did Soren make an error?
Answer:
step 3 didn't divide by 2
Step-by-step explanation:
in step
[tex] \frac{ - 8 + \sqrt{100} }{2} = \frac{ - 8 + 10}{2} = 1 \\ \frac{ - 8 - \sqrt{100} }{2} = \frac{ - 8 - 10}{2} = - 9[/tex]
How far does the barnacle travel in one revolution of the water wheel?
m
Answer:
2pi
Step-by-step explanation:
Right on edg assignment
Find the area of following rhombuses. Round your answers to the nearest tenth if
necessary.
Answer:
[tex]Area =55.4ft^2[/tex]
Step-by-step explanation:
Given
The attached rhombus
Required
The area
First, calculate the length of half the vertical diagonal (x).
Length x is represented as the adjacent to 60 degrees
So, we have:
[tex]\tan(60) = \frac{4\sqrt 3}{x}[/tex]
Solve for x
[tex]x = \frac{4\sqrt 3}{\tan(60)}[/tex]
[tex]\tan(60) = \sqrt 3[/tex]
So:
[tex]x = \frac{4\sqrt 3}{\sqrt 3}[/tex]
[tex]x = 4[/tex]
At this point, we have established that the rhombus is made up 4 triangles of the following dimensions
[tex]Base = 4\sqrt 3[/tex]
[tex]Height = 4[/tex]
So, the area of the rhombus is 4 times the area of 1 triangle
[tex]Area = 4 * \frac{1}{2} * Base * Height[/tex]
[tex]Area = 4 * \frac{1}{2} * 4\sqrt 3 * 4[/tex]
[tex]Area =2 * 4\sqrt 3 * 4[/tex]
[tex]Area =55.4ft^2[/tex]
Find the 9th term of the geometric sequence 5, -25, 125, ...
Answer: 1,953,125
This is one single value and it is just a bit under 2 million.
Or more accurately, it's a bit over 1.9 million.
===========================================================
Explanation:
a = 5 = first termr = -5 = common ratioNote that dividing any term by its previous term gets us the common ratio
r = term2/term1 = -25/5 = -5r = term3/term2 = 125/(-5) = -5The r value must stay the same the entire time, or else the sequence isn't geometric.
The nth term of any geometric sequence is a*(r)^(n-1). With the 'a' and 'r' values we found, we update that to 5(-5)^(n-1)
-----------------
To verify that is the correct nth term expression, plug in various values of n to compare it with the given sequence.
If we tried n = 2 for instance, then we find the 2nd term is
5(-5)^(n-1) = 5(-5)^(2-1) = -25
which matches what your teacher gave you. I'll let you verify the other terms.
-----------------
The last thing we need to do is plug in n = 9 and simplify
5(-5)^(n-1)
5(-5)^(9-1)
5(-5)^8
5(390625)
1,953,125 this is one single value (rather than 3 separate values)
Luci and her friends go out to lunch and receive a bill
for their meals that reads $56.80. They added a 20%
tip to their bill before tax was calculated. Tax is 8%.
How much money did they leave in total, including tax
and tip? Round to the nearest cent. Show your work.
Answer:
$72.70
Step-by-step explanation:
bill was $56.80
tip was 20% so was 56.80/ 5( because 5 of 20% will make 100%)= $11.36
tax was 8% so was 56.80*8/100= $4.54
total money paid
56.80+4.54+11.36 = 72.70
The probability that a tennis set will go to a tiebreaker is 16%. In 220 randomly selected tennis sets, what is the mean and the standard deviation of the number of tiebreakers
Answer:
The mean number of tiebreakers is of 35.2 and the standard deviation is of 5.44.
Step-by-step explanation:
For each set, there are only two possible outcomes. Either it goes to a tiebreak, or it does not. The probability of a set going to a tiebreak is independent of any other set, which means that the binomial probability distribution is used to solve this question.
Binomial probability distribution
Probability of exactly x successes on n repeated trials, with p probability.
The expected value of the binomial distribution is:
[tex]E(X) = np[/tex]
The standard deviation of the binomial distribution is:
[tex]\sqrt{V(X)} = \sqrt{np(1-p)}[/tex]
The probability that a tennis set will go to a tiebreaker is 16%.
This means that [tex]p = 0.16[/tex]
220 randomly selected tennis sets
This means that [tex]n = 220[/tex]
What is the mean and the standard deviation of the number of tiebreakers?
[tex]E(X) = np = 220*0.16 = 35.2[/tex]
[tex]\sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{220*0.16*0.84} = 5.44[/tex]
The mean number of tiebreakers is of 35.2 and the standard deviation is of 5.44.
Can someone help me
Answer:
y= (-6/5)x -2
Step-by-step explanation:
y=mx+b , where m is the slope, and b is the y -intercept
the y -intercept is where the line intersects the y-axis so b = -2
the slope m= y(rise) /x(run) = 6/-5 = -6/5 ( to find the slope you have to know how to get from any point on the line to another point on the same line; start at point (0,-2) go up 6(y-rise) and to the left 5(x-run) at point (-5,4))
y= (-6/5)x -2
Help me ask me if you want brainly
Answer:
the answer is a!
Step-by-step explanation:
Ignore the instructions if you know how to do it in a different way & please check answer!
~Rules~
a. NO LINKS/FILES
b. NO SILLY ANSWER
c. SHOW WORK/EXPLAIN HOW YOU GOT IT
If you follow all the rules I will give Brainliest.
~Hocus Pocus
Answer:
8ft is the diameter so the radius would be half of that, so it's 4ft. Now substitute
[tex]\pi4 {}^{2} [/tex]
now solve 4^2=16 now multiply it by 3.14 (pi). 16×3.14= 50.24
HELPPP PLSS ILL GIVE BRANILEST!!!
Answer:
either 22/60 or .3666 recurring
Step-by-step explanation:
All you are doing is converting minutes to hours basically, so all you have to do is divide 22 by 60.
What is the volume of the given picture below? ( HELP PLEASE )
Helpp
Based on the histogram above, which of the following statements must be true
Answer:
b
Step-by-step explanation:
because the price of money is maximum 2,500
A factory that manufactures bolts is performing a quality control experiment. Each object should have a length of no more than
12
centimeters. The factory believes that the length of the bolts exceeds this value and measures the length of
76
bolts. The sample mean bolt length was
12.07
centimeters. The population standard deviation is known to be
σ
=
0.28
centimeters.
What is the test statistic
z
?
What is the
p
-value?
Does sufficient evidence exist that the length of bolts is actually greater than the mean value at a significance level of
α
=
0.1
?
Answer:i dont know
Step-by-step explanation:
GUYS QUICK! what is the surface area of a sphere that has a radius of 5 cm
Answer:
100 pi cm^2
or approximately 314 cm^2
Step-by-step explanation:
The surface area of a sphere is given by
SA = 4 pi r^2
The radius is 5
SA = 4 *pi * 5^2
SA = 4*pi(25
SA = 100 pi cm^2
If pi is 3.14
SA = 100 *3.14 = 314 cm^2
[tex]\large\fbox{\underline{Surfαcє αrєα σf sphєrє ís 314 cm ².}}[/tex]
Step-by-step explanation:◈ Gívєn ◈☞ Rαdíus σf sphєrє = 5 cm
◈ Tσ FínD ◈☞ Surfαcє αrєα σf sphєrє
◈ Fσrmulα nєєdєd ◈☞ Surfαcє αrєα σf sphєrє = 4 π r ²
◈ Sσlutíσn ◈usíng thє fσrmulα
surfαcє αrєα σf sphєrє = 4 π r ²
suвstítutє thє vαluєs
surfαcє αrєα σf sphєrє = 4 × 3.14 × ( 5×5 ) cm ²
mutíplчíng thє vαluєs
surfαcє αrєα σf sphєrє = 100 cm² × 3.14
Hєncє , Surfαcє αrєα σf sphєrє ís 314cm ².
–––––––––☆–––––––––The confidence interval is pretty wide and leaves a lot of uncertainty over the proportion of UCI students who live on campus. With the goal to estimate a narrower 95% confidence interval, what is a simple change to this study that you could suggest for the next time that a similar survey is conducted
Answer:
Following are the solution to the given question:
Step-by-step explanation:
Researchers must increase the response rate to achieve a narrower confidence interval. Because we see that the trust gap is inverse to sample size. We must increase data in estimating a narrower 95-percent trust range. Since the sample has increased, its error margin has decreased, this reduces the width of the trust interval.